In managing diabetes, it is well known that wellness is related to glucose level, and that blood glucose level is affected by exertion level (calories consumed) and diet. The calories consumed are related to the speed and force of movement and the mass of the subject. Walking uphill consumes more calories than downhill, or on a level, and running consumes more per unit time than walking. Existing pedometers do not account for vertical vs. horizontal acceleration, and require a particular orientation to differentiate these two axes to thereby determine steps taken and calorie expended (when the weight of the subject is known). This makes them difficult to use, and affects the accuracy of the results (if they are oriented wrongly and this is not detected).
Existing glucometers (which determines blood glucose level) and pedometers do not interact so as to correlate results from the glucometer with calories expended (based on the pedometer results). Such correlation can be used effectively to adjust the actions the subject takes, i.e., a low glucose level can be the result of exertion, and the subject could be instructed to reduce activity level rather than consuming carbohydrates.
One design of existing glucometers employs glucose dehydrogenase to generate electrons on a strip covered with blood, and the change in voltage across the strip is measured over time to determine glucose concentration. Resistance across the strip drops over time due to the chemistry of the strip and the increase in the product of the enzyme-catalyzed reaction. Measurement of the corresponding voltage drop is correlated with known blood glucose concentrations to determine the subject's blood glucose concentration.
The disadvantages of such glucometers include that they are noise sensitive, as voltage is calculated directly from the current flow. Noise-resistant designs are thus desirable.
There is also a need to measure exertion levels of the subject, then readily transmit data from glucometers and exertion measurement devices (e.g., pedometers) to a monitor, who can determine what instructions to provide the patient to maintain blood glucose at optimal levels. The transmission medium should be inexpensive and widely used, to avoid added costs.